The estimated grade is the result of many factors including word choice, spelling, grammar,
and more. The other feedback given by our service should provide you with clues as to
how to improve your grade. Please note that the auto-grader is not able to analyze your ideas,
how well you support your main points, the logic of your statements, the organization of your text,
and more. Scores on creative writing do not always transfer as well due to the computer's inability
to evaluate analogies and other clever constructs. Any more information on this would require discussion of statistics,
machine learning, and natural language processing...(Exciting to us, but not to most people)

We are focused primarily on growth at this point (we are a startup), but we offer a premium membership for those interested in more features. Costs are also offset by the ads that you may have noticed on some pages of our site.

There is an error in my paper that was not detected by PaperRater. Why is that?

There are a few possible reasons for this. PaperRater looks for common errors, and your mistake may not be one that it recognizes. In addition, PaperRater only suggests changes when its statistical models are confident that there is a problem, so that users aren't presented with many "false positives". We don't want to mention any names, but we have found other popular grammar checkers to be wrong in 25-45% of the instances they flag.

Your service tells me that there's a mistake in my paper, but I am certain that my writing is correct. How is this?

We do our best to minimize these instances of "false positives", but our software and statistical models are not perfect. You can email us the sentence in question along with the message, and this info will help to improve our system.

Why is the suggestion given for one of my mistakes worse than the original mistake?

Ouch, that hurts. Grendel (our automated proofreading software) attempts to find the best correction using techniques available to computers. He lacks the full contextual understanding of a human and is semantically-challenged. To help Grendel improve, please email us the problem sentence and the bad suggestion.

Should a teacher use the grade given by PaperRater as the student's final grade on a paper?

Most teachers would like students' grades to reflect the standards set forth by that particular teacher for that particular class. For example, a high school may have three different writing levels (and classes) within the same grade level (e.g., Senior). Even if each class has the same teacher, he/she would grade each class differently. For example, an AP English class would not be graded the same as a basic level classroom.
In addition, it's important to note that the automated grader does not take into account all features of the text. Evaluating the organization of the text and the arguments made is still something that we leave up to the teacher.

I submitted my paper to your site and then my computer crashed before I had a chance to save the paper. Can you send me my paper?

As much as we are sorry for your loss, we cannot assist with these requests. Most papers are deleted from our system within hours of being submitted. Moreover, there would be thorny privacy issues to navigate even if we were able to respond quick enough to retrieve your paper.

We allow 6 pages at roughly 300 words/page for our free service. We have a premium service at http://premium.PaperRater.com that allows up to 15 pages. If we go higher than that, Grendel can't fully digest your submission (he gets indigestion). Of course, if your paper exceeds the limit, you are welcome to split it up into multiple submissions.